Increasing corrosion rate

I am currently researching the relationship between ambient temperature
and corrosion rate on steel. These steel pieces are currently tested
with a 5% NaCl @ 35degC salt spray (as per ASTM B117) for 1000 hours.
I am charged with finding a way to reduce this testing time.
This topic has been widely discussed in a number of forums and
websites, and everyone seems to agree that increasing the ambient
temperature (until a certain point) will increase the corrosion rate.
However, I have found no documents to support this claim, nor any
definitive relationship between corrosion rate and temperature.
I am not a chemist or chemical engineer, merely an intern. Can anyone
point me in the right direction? Thanks.
-Kevin
Reply to
dengetek
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Are you really researching Temp vs corrosion rate, or are you charged with finding a way to reduce testing time on steel samples? The two things are different.
If the latter, then I suggest you take a look at ASTM G85, a much more rigorous test.
cheers
Reply to
Harry Andreas
The issue is that we were told a certain type of coating would last 1000 hours in a salt spray test with 5% salt @ 35degC, and we want to verify that this is true in a shorter time.
I made a mistake in my original post. The products are actually made of aluminum, not steel. And I also made the mistake of saying the corrosion rate of the steel (or aluminum) instead of the coating. Sorry for the mix up! I'm still learning. However, I think this would be inconsequential if I could determine a (such as the Arrhenius equation) corrosion rate vs. temperature relationship in any material undergoing a salt spray test.
I am not sure that the Arrhenius equation applies though, since this is a 'spray' test, not a 'bath' test. Is this correct? Wouldn't the corrosion rate also depend on the pressure of the spray?
Thanks.
-Kevin
Reply to
dengetek

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